1. Field of the Invention
This invention relates to control apparatus, and more particularly to radio tuning control apparatus, said apparatus being adapted to be mounted in a variety of different support structures, each having different locations for control shafts.
2. Description of the Prior Art
Automotive entertainment radios are usually positioned behind the dashboard of an automobile and have a pair of shafts extending through apertures formed in the dashboard, providing manual volume control and manual tuning control. A tuning dial portion of the radio also extends through an aperture in the dashboard. Many radios also have push buttons for automatically selecting one of a predetermined set of operating frequencies. The dial display, the tuner mechanism, and the push-button keys, if used, generally are part of a tuner module affixed to a front plate. The front plate forms a part of the support housing for the radio receiver apparatus and also provides for mounting the radio apparatus to the dashboard. The control shafts for the radio receiver are also mounted to the front panel. The openings in the dashboard of an automobile for the dial display, the key buttons, and the control shafts have predetermined fixed locations for each of the many automobile models available. The relative position of the openings in the dashboard vary somewhat between the different models. Manufacturers and aftermarket suppliers of automotive radios, therefore, must make provisions to supply appropriately configured radio receivers to fit the various dashboard opening configurations.
It has long been recognized that a universally mountable radio would be very desirable. A manufacturer or supplier of such a radio would then be able to supply one basic radio receiver which would be accommodated by all dashboard opening configurations. With such a universally mountable radio, for example, the tuner mechanism shaft which drives the radio receiver tuning element and which is located usually at a distance from the front panel of the radio would be controlled by a variably positioned driving shaft. The shaft would be located on the front panel in a position depending upon the location of the dashboard opening.
One solution to this problem has been to provide a distinct configuration of driving shaft and associated support structure for each dashboard configuration. In many cases, this approach also requires that the tuner shaft length, as well as the support structure for both the driving shaft and the tuning shaft, be changed for each configuration.
Other somewhat more flexible approaches to solving the problem have been taken. One of these approaches involves using a series of discs and pinch washers, a disc being pinched between peripheral portions of a pinch washer. The disc and pinch washer approach performs the same functions as a series of intermeshing gears would. The disc and pinch washer approach, in particular, suffers from slippage and because of the requisite pinching action requires high torque, both undesirable features in an entertainment automotive radio receiver. The locus of positions for both the disc and pinch washer and the gear coupling mechanisms both are limited requiring the control shafts to be positioned on very restricted arcs of circles and portions of straight lines.
As is evident, providing for an individually designed control apparatus for each dashboard configuration and providing control apparatus having limited range of positions necessarily adds to cost and prevents an automotive radio receiver from being universally mountable in all possible dashboard configurations.
A particular kind of link coupling apparatus is provided in the prior art for coupling the shafts of two pieces of heavy rotating machinery when the shafts thereof are parallel but not coaxial. The coupler provided in the prior art has coupling bars which are rotatable about pins fixed to disc members, the rotation of the links being required to be confined to a plane perpendicular to the axes of the shafts. Pivotal movement of the links about the pins, that is, movement in planes other than perpendicular to the axes of the shaft is not provided by these prior art couplers so that the shafts may not be moved out of parallel alignment.